Poly(arylene ether) resins may be prepared by the oxidative polymerization of a monohydric phenol in the presence of a solvent to form a solution in which the product poly(arylene ether) is soluble. The poly(arylene ether) may then be isolated by combining the solution with an antisolvent to precipitate the poly(arylene ether). In practice, it is very challenging to control these precipitations to provide a final poly (arylene ether) solid having consistent particle size. In some cases, substantial quantities of unacceptable poly(arylene ether) may be produced before the problem is recognized or addressed. In other cases, poly(arylene ether) particles may be formed that adversely affect the process by, for example, blocking transport pipes or a filtration unit. There is a need for a method of precipitating a poly(arylene ether) that enables rapid adjustment of precipitation conditions to maintain a desired particle size distribution within the process and in the final product.
The above-described and other drawbacks and disadvantages are alleviated by a method comprising: preparing a poly(arylene ether) solution comprising a poly(arylene ether) and a solvent; combining the poly(arylene ether) solution with an antisolvent to form a poly(arylene ether) dispersion comprising a poly(arylene ether) solid; separating the poly(arylene ether) solid from the poly(arylene ether) dispersion to form an isolated poly(arylene ether) solid; determining a particle size distribution of the poly(arylene ether) solid prior to the separating the poly(arylene ether) solid from the poly(arylene ether) dispersion; and adjusting a precipitation parameter in response to the particle size distribution.
Other embodiments, including an apparatus for carrying out the method, are described in detail below.